#include<iostream>
#include<queue>
#include<stack>

int main()
{
    std::queue<int> s;
    s.push(1);
    s.push(2);
    while(!s.empty())
    {
        std::cout<<s.front()<<" ";
        s.pop();
    }
    std::cout<<std::endl;




    return 0;
}